This is busybox's unmodified copy_file() in libbb/copy_file.c from the
GPL2+ commit f2c043acfcf9dad9fd3d65821b81f89986bbe54e (busybox: fix
uninitialized memory when displaying IPv6 addresses -
2016-01-18). This is a no-op commit. More changes are needed before
this new code can compile.
This will be needed for implementing "git worktree move" where we have
to move a directory recursively. We can implement it from scratch, but
then we will have to deal with corner cases (failure to move, circular
symlinks...). And delegating the task to "/bin/mv" takes a way the
ability to clean things up properly when things fail and we may have
to deal with "mv" differences between platforms.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@xxxxxxxxx>
---
copy.c | 331 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 331 insertions(+)
diff --git a/copy.c b/copy.c
index 4de6a11..79623ac 100644
--- a/copy.c
+++ b/copy.c
@@ -65,3 +65,334 @@ int copy_file_with_time(const char *dst, const char *src, int mode)
return copy_times(dst, src);
return status;
}
+
+#if 0
+/* Return:
+ * -1 error, copy not made
+ * 0 copy is made or user answered "no" in interactive mode
+ * (failures to preserve mode/owner/times are not reported in exit code)
+ */
+int FAST_FUNC copy_file(const char *source, const char *dest, int flags)
+{
+ /* This is a recursive function, try to minimize stack usage */
+ /* NB: each struct stat is ~100 bytes */
+ struct stat source_stat;
+ struct stat dest_stat;
+ smallint retval = 0;
+ smallint dest_exists = 0;
+ smallint ovr;
+
+/* Inverse of cp -d ("cp without -d") */
+#define FLAGS_DEREF (flags & (FILEUTILS_DEREFERENCE + FILEUTILS_DEREFERENCE_L0))
+
+ if ((FLAGS_DEREF ? stat : lstat)(source, &source_stat) < 0) {
+ /* This may be a dangling symlink.
+ * Making [sym]links to dangling symlinks works, so... */
+ if (flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK))
+ goto make_links;
+ bb_perror_msg("can't stat '%s'", source);
+ return -1;
+ }
+
+ if (lstat(dest, &dest_stat) < 0) {
+ if (errno != ENOENT) {
+ bb_perror_msg("can't stat '%s'", dest);
+ return -1;
+ }
+ } else {
+ if (source_stat.st_dev == dest_stat.st_dev
+ && source_stat.st_ino == dest_stat.st_ino
+ ) {
+ bb_error_msg("'%s' and '%s' are the same file", source, dest);
+ return -1;
+ }
+ dest_exists = 1;
+ }
+
+#if ENABLE_SELINUX
+ if ((flags & FILEUTILS_PRESERVE_SECURITY_CONTEXT) && is_selinux_enabled() > 0) {
+ security_context_t con;
+ if (lgetfilecon(source, &con) >= 0) {
+ if (setfscreatecon(con) < 0) {
+ bb_perror_msg("can't set setfscreatecon %s", con);
+ freecon(con);
+ return -1;
+ }
+ } else if (errno == ENOTSUP || errno == ENODATA) {
+ setfscreatecon_or_die(NULL);
+ } else {
+ bb_perror_msg("can't lgetfilecon %s", source);
+ return -1;
+ }
+ }
+#endif
+
+ if (S_ISDIR(source_stat.st_mode)) {
+ DIR *dp;
+ const char *tp;
+ struct dirent *d;
+ mode_t saved_umask = 0;
+
+ if (!(flags & FILEUTILS_RECUR)) {
+ bb_error_msg("omitting directory '%s'", source);
+ return -1;
+ }
+
+ /* Did we ever create source ourself before? */
+ tp = is_in_ino_dev_hashtable(&source_stat);
+ if (tp) {
+ /* We did! it's a recursion! man the lifeboats... */
+ bb_error_msg("recursion detected, omitting directory '%s'",
+ source);
+ return -1;
+ }
+
+ if (dest_exists) {
+ if (!S_ISDIR(dest_stat.st_mode)) {
+ bb_error_msg("target '%s' is not a directory", dest);
+ return -1;
+ }
+ /* race here: user can substitute a symlink between
+ * this check and actual creation of files inside dest */
+ } else {
+ /* Create DEST */
+ mode_t mode;
+ saved_umask = umask(0);
+
+ mode = source_stat.st_mode;
+ if (!(flags & FILEUTILS_PRESERVE_STATUS))
+ mode = source_stat.st_mode & ~saved_umask;
+ /* Allow owner to access new dir (at least for now) */
+ mode |= S_IRWXU;
+ if (mkdir(dest, mode) < 0) {
+ umask(saved_umask);
+ bb_perror_msg("can't create directory '%s'", dest);
+ return -1;
+ }
+ umask(saved_umask);
+ /* need stat info for add_to_ino_dev_hashtable */
+ if (lstat(dest, &dest_stat) < 0) {
+ bb_perror_msg("can't stat '%s'", dest);
+ return -1;
+ }
+ }
+ /* remember (dev,inode) of each created dir.
+ * NULL: name is not remembered */
+ add_to_ino_dev_hashtable(&dest_stat, NULL);
+
+ /* Recursively copy files in SOURCE */
+ dp = opendir(source);
+ if (dp == NULL) {
+ retval = -1;
+ goto preserve_mode_ugid_time;
+ }
+
+ while ((d = readdir(dp)) != NULL) {
+ char *new_source, *new_dest;
+
+ new_source = concat_subpath_file(source, d->d_name);
+ if (new_source == NULL)
+ continue;
+ new_dest = concat_path_file(dest, d->d_name);
+ if (copy_file(new_source, new_dest, flags & ~FILEUTILS_DEREFERENCE_L0) < 0)
+ retval = -1;
+ free(new_source);
+ free(new_dest);
+ }
+ closedir(dp);
+
+ if (!dest_exists
+ && chmod(dest, source_stat.st_mode & ~saved_umask) < 0
+ ) {
+ bb_perror_msg("can't preserve %s of '%s'", "permissions", dest);
+ /* retval = -1; - WRONG! copy *WAS* made */
+ }
+ goto preserve_mode_ugid_time;
+ }
+
+ if (flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK)) {
+ int (*lf)(const char *oldpath, const char *newpath);
+ make_links:
+ /* Hmm... maybe
+ * if (DEREF && MAKE_SOFTLINK) source = realpath(source) ?
+ * (but realpath returns NULL on dangling symlinks...) */
+ lf = (flags & FILEUTILS_MAKE_SOFTLINK) ? symlink : link;
+ if (lf(source, dest) < 0) {
+ ovr = ask_and_unlink(dest, flags);
+ if (ovr <= 0)
+ return ovr;
+ if (lf(source, dest) < 0) {
+ bb_perror_msg("can't create link '%s'", dest);
+ return -1;
+ }
+ }
+ /* _Not_ jumping to preserve_mode_ugid_time:
+ * (sym)links don't have those */
+ return 0;
+ }
+
+ if (/* "cp thing1 thing2" without -R: just open and read() from thing1 */
+ !(flags & FILEUTILS_RECUR)
+ /* "cp [-opts] regular_file thing2" */
+ || S_ISREG(source_stat.st_mode)
+ /* DEREF uses stat, which never returns S_ISLNK() == true.
+ * So the below is never true: */
+ /* || (FLAGS_DEREF && S_ISLNK(source_stat.st_mode)) */
+ ) {
+ int src_fd;
+ int dst_fd;
+ mode_t new_mode;
+
+ if (!FLAGS_DEREF && S_ISLNK(source_stat.st_mode)) {
+ /* "cp -d symlink dst": create a link */
+ goto dont_cat;
+ }
+
+ if (ENABLE_FEATURE_PRESERVE_HARDLINKS && !FLAGS_DEREF) {
+ const char *link_target;
+ link_target = is_in_ino_dev_hashtable(&source_stat);
+ if (link_target) {
+ if (link(link_target, dest) < 0) {
+ ovr = ask_and_unlink(dest, flags);
+ if (ovr <= 0)
+ return ovr;
+ if (link(link_target, dest) < 0) {
+ bb_perror_msg("can't create link '%s'", dest);
+ return -1;
+ }
+ }
+ return 0;
+ }
+ add_to_ino_dev_hashtable(&source_stat, dest);
+ }
+
+ src_fd = open_or_warn(source, O_RDONLY);
+ if (src_fd < 0)
+ return -1;
+
+ /* Do not try to open with weird mode fields */
+ new_mode = source_stat.st_mode;
+ if (!S_ISREG(source_stat.st_mode))
+ new_mode = 0666;
+
+ // POSIX way is a security problem versus (sym)link attacks
+ if (!ENABLE_FEATURE_NON_POSIX_CP) {
+ dst_fd = open(dest, O_WRONLY|O_CREAT|O_TRUNC, new_mode);
+ } else { /* safe way: */
+ dst_fd = open(dest, O_WRONLY|O_CREAT|O_EXCL, new_mode);
+ }
+ if (dst_fd == -1) {
+ ovr = ask_and_unlink(dest, flags);
+ if (ovr <= 0) {
+ close(src_fd);
+ return ovr;
+ }
+ /* It shouldn't exist. If it exists, do not open (symlink attack?) */
+ dst_fd = open3_or_warn(dest, O_WRONLY|O_CREAT|O_EXCL, new_mode);
+ if (dst_fd < 0) {
+ close(src_fd);
+ return -1;
+ }
+ }
+
+#if ENABLE_SELINUX
+ if ((flags & (FILEUTILS_PRESERVE_SECURITY_CONTEXT|FILEUTILS_SET_SECURITY_CONTEXT))
+ && is_selinux_enabled() > 0
+ ) {
+ security_context_t con;
+ if (getfscreatecon(&con) == -1) {
+ bb_perror_msg("getfscreatecon");
+ return -1;
+ }
+ if (con) {
+ if (setfilecon(dest, con) == -1) {
+ bb_perror_msg("setfilecon:%s,%s", dest, con);
+ freecon(con);
+ return -1;
+ }
+ freecon(con);
+ }
+ }
+#endif
+ if (bb_copyfd_eof(src_fd, dst_fd) == -1)
+ retval = -1;
+ /* Careful with writing... */
+ if (close(dst_fd) < 0) {
+ bb_perror_msg("error writing to '%s'", dest);
+ retval = -1;
+ }
+ /* ...but read size is already checked by bb_copyfd_eof */
+ close(src_fd);
+ /* "cp /dev/something new_file" should not
+ * copy mode of /dev/something */
+ if (!S_ISREG(source_stat.st_mode))
+ return retval;
+ goto preserve_mode_ugid_time;
+ }
+ dont_cat:
+
+ /* Source is a symlink or a special file */
+ /* We are lazy here, a bit lax with races... */
+ if (dest_exists) {
+ errno = EEXIST;
+ ovr = ask_and_unlink(dest, flags);
+ if (ovr <= 0)
+ return ovr;
+ }
+ if (S_ISLNK(source_stat.st_mode)) {
+ char *lpath = xmalloc_readlink_or_warn(source);
+ if (lpath) {
+ int r = symlink(lpath, dest);
+ free(lpath);
+ if (r < 0) {
+ bb_perror_msg("can't create symlink '%s'", dest);
+ return -1;
+ }
+ if (flags & FILEUTILS_PRESERVE_STATUS)
+ if (lchown(dest, source_stat.st_uid, source_stat.st_gid) < 0)
+ bb_perror_msg("can't preserve %s of '%s'", "ownership", dest);
+ }
+ /* _Not_ jumping to preserve_mode_ugid_time:
+ * symlinks don't have those */
+ return 0;
+ }
+ if (S_ISBLK(source_stat.st_mode) || S_ISCHR(source_stat.st_mode)
+ || S_ISSOCK(source_stat.st_mode) || S_ISFIFO(source_stat.st_mode)
+ ) {
+ if (mknod(dest, source_stat.st_mode, source_stat.st_rdev) < 0) {
+ bb_perror_msg("can't create '%s'", dest);
+ return -1;
+ }
+ } else {
+ bb_error_msg("unrecognized file '%s' with mode %x", source, source_stat.st_mode);
+ return -1;
+ }
+
+ preserve_mode_ugid_time:
+
+ if (flags & FILEUTILS_PRESERVE_STATUS
+ /* Cannot happen: */
+ /* && !(flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK)) */
+ ) {
+ struct timeval times[2];
+
+ times[1].tv_sec = times[0].tv_sec = source_stat.st_mtime;
+ times[1].tv_usec = times[0].tv_usec = 0;
+ /* BTW, utimes sets usec-precision time - just FYI */
+ if (utimes(dest, times) < 0)
+ bb_perror_msg("can't preserve %s of '%s'", "times", dest);
+ if (chown(dest, source_stat.st_uid, source_stat.st_gid) < 0) {
+ source_stat.st_mode &= ~(S_ISUID | S_ISGID);
+ bb_perror_msg("can't preserve %s of '%s'", "ownership", dest);
+ }
+ if (chmod(dest, source_stat.st_mode) < 0)
+ bb_perror_msg("can't preserve %s of '%s'", "permissions", dest);
+ }
+
+ if (flags & FILEUTILS_VERBOSE) {
+ printf("'%s' -> '%s'\n", source, dest);
+ }
+
+ return retval;
+}
+#endif
--
2.8.2.524.g6ff3d78